Dual optical and electrical LGA contact

ABSTRACT

A method and structure are provided for implementing a dual optical and electrical land grid array (LGA) contact. A contact for electrical and optical connection between a module and a printed circuit board (PCB) includes material providing electrical connection and an integrated material providing an optical connection; and the contact is used in a land grid array (LGA) arrangement.

This application is a continuation application of Ser. No. 14/585,411filed Dec. 30, 2014.

FIELD OF THE INVENTION

The present invention relates generally to the data processing field,and more particularly, relates to a method and structures forimplementing a dual optical and electrical land grid array (LGA)contact.

DESCRIPTION OF THE RELATED ART

Current sockets that incorporate optical routing typically utilizelenses to direct optical signals to the board or an entirely separateoptical module to route optical signals away from the board. In eithercase, valuable LGA contacts must be removed to make space for theoptical pathway away from the module.

A need exists for a method and structure to attach a compact, highdensity optical and electrical module (i.e. CPU) in a non-permanentfashion (LGA Socket) while maintaining good electrical and opticaltransmission.

SUMMARY OF THE INVENTION

Principal aspects of the present invention are to provide a method andstructures for implementing a dual optical and electrical land gridarray (LGA) contact. Other important aspects of the present inventionare to provide such method and structure substantially without negativeeffects and that overcome many of the disadvantages of prior artarrangements.

In brief, a method and structures are provided for implementing a dualoptical and electrical land grid array (LGA) contact. A contact forelectrical and optical connection between a module and a printed circuitboard (PCB) includes material providing electrical connection and anintegrated material providing an optical connection; and the contact isconfigured for use in a land grid array (LGA) arrangement.

In accordance with features of the invention, the contact includes a LGAspring type contact with a core filled with an acrylic or other lightpipe style material. The LGA spring type contact provides an electricalsignal pathway to the PCB, while the center light pipe provides anoptical route.

In accordance with features of the invention, the act of compressing theLGA spring type contact also greatly limits the air gap and hence thelight loss from the module to the PCB trace.

In accordance with features of the invention, the structures enable acompact, high density optical and electrical module, for example a CPUmodule to attach in a non-permanent fashion such as with an LGA socketwhile maintaining good electrical and optical transmission. Thestructures allow the module to connect to dual optical-electricaltraces.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention together with the above and other objects andadvantages may best be understood from the following detaileddescription of the preferred embodiments of the invention illustrated inthe drawings, wherein:

FIG. 1 illustrates an example prior art electrical land grid array (LGA)contact;

FIG. 2 illustrates an example structure for implementing a dual opticaland electrical land grid array (LGA) contact in accordance with thepreferred embodiment;

FIG. 3 illustrates another example structure for implementing a dualoptical and electrical land grid array (LGA) contact in accordance withthe preferred embodiment; and

FIG. 4 illustrates another example structure for implementing a dualoptical and electrical land grid array (LGA) contact in accordance withthe preferred embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following detailed description of embodiments of the invention,reference is made to the accompanying drawings, which illustrate exampleembodiments by which the invention may be practiced. It is to beunderstood that other embodiments may be utilized and structural changesmay be made without departing from the scope of the invention.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

In accordance with features of the invention, a method and structuresare provided for implementing a dual optical and electrical land gridarray (LGA) contact. A contact for electrical and optical connectionbetween a module and a printed circuit board (PCB) includes materialproviding electrical connection and an integrated material providing anoptical connection; and the contact is configured for use in a land gridarray (LGA) arrangement in accordance with preferred embodiments.

Having reference now to the drawings, in FIG. 1, there is shown anexample prior art electrical land grid array (LGA) contact generallydesignated by reference character 100.

The prior art electrical LGA contact structure 100 includes a typicalhybrid LGA contact profile generally designated by reference character102 in accordance with preferred embodiments. The prior art electricalLGA contact structure 100 engages a lower solder ball 104 for electricalconnection with a PCB (not shown). The prior art electrical LGA contactstructure 100 includes a lower portion 106 extending between the solderball 104 and an upper portion 108.

Referring to FIG. 2, there is shown an example structure forimplementing a dual optical and electrical land grid array (LGA) contactgenerally designated by reference character 200 in accordance with thepreferred embodiment.

The dual optical and electrical LGA contact structure 200 provideselectrical and optical connection between a module and a printed circuitboard (PCB) (not shown) includes material providing electricalconnection and an integrated material providing an optical connection.The dual optical and electrical LGA contact structure 200 is configuredfor use in a land grid array (LGA) arrangement in accordance withpreferred embodiments.

The dual optical and electrical LGA contact structure 200 includes anLGA contact profile generally designated by reference character 202 inaccordance with preferred embodiments. The dual optical and electricalLGA contact structure 200 includes a lower flat portion 204 forelectrical connection and optical connection with a PCB (not shown). Thedual optical and electrical LGA contact structure 200 includes a middleportion 206 extending between the lower contact portion 204 and an upperportion 208.

The dual optical and electrical LGA contact structure 200 shown in crosssection includes an interior or middle portion 210 filled with anacrylic or other light pipe style material. The LGA spring type contact200 provides an electrical signal pathway provided by the exteriorportions 212, while the middle light pipe 210 provides an optical route.The interior portion 210 filled with an acrylic or other light pipestyle material extends from the upper contact portion 208 to the lowercontact portion 204 providing optical contact with the PCB.

Referring to FIG. 3, there is shown another example structure forimplementing a dual optical and electrical land grid array (LGA) contactgenerally designated by reference character 300 in accordance with thepreferred embodiment. As shown, the dual optical and electrical LGAcontact structure 300 provides a view of the contact top generallydesignated by reference character 302. The dual optical and electricalLGA contact structure 300 is similar to embodiment of the dual opticaland electrical LGA contact structure 200, but with dual optical paths304 provided along opposed outer portions 304, allowing a centerelectrical contact generally designated by reference character 306 to bemaintained.

Referring to FIG. 4, there is shown another example structure forimplementing a dual optical and electrical land grid array (LGA) contactgenerally designated by reference character 400 in accordance withpreferred embodiments.

The dual optical and electrical LGA contact structure 400 includes anLGA contact profile generally designated by reference character 402 inaccordance with preferred embodiments. The dual optical and electricalLGA contact structure 400 includes a lower flat portion 404 forelectrical connection and optical connection with a PCB (not shown). Thedual optical and electrical LGA contact structure 400 includes a middleportion 406 extending between the lower ball shaped portion 404 and anupper portion 408.

The dual optical and electrical LGA contact structure 400 is formed witha respective hole 409A, 409B in lower portion 404 and the upper portion408 and injected with light pipe style material 410 and formed to theappropriate shape. The LGA spring type contact 400 provides anelectrical signal pathway provided by opposed split electricalconnection exterior portions 412, while the middle light pipe 210provides an optical route. The widened region of the light pipe 410 atthe top portion 408 is slightly recessed from the metal contact surface412 of the LGA pin to ensure that good electrical contact occurs. Lightis sent from the module base (not shown) and into the LGA light pipe 410through the wide receiving side at the top portion 408. Light is thentransmitted through the light pipe portion 410 and emitted at the baseportion 404, into the receiving side of the board (not shown).

While the present invention has been described with reference to thedetails of the embodiments of the invention shown in the drawing, thesedetails are not intended to limit the scope of the invention as claimedin the appended claims.

What is claimed is:
 1. A method for implementing a dual optical andelectrical land grid array (LGA) contact comprising: providing a contactseparately providing both electrical and optical connection between amodule and a printed circuit board (PCB); providing said contact with amaterial providing electrical connection and an integrated materialproviding an optical connection; providing said contact configured foruse in a land grid array (LGA) arrangement; each said contact providinga dual optical and electrical land grid array (LGA) contact having saidelectrical connection contact material disposed proximate to saidoptical connection integrated material and including a lower flatcontact portion providing electrical connection and optical connectionwith the printed circuit board (PCB); said electrical connection contactmaterial and said optical connection integrated material extendingbetween the lower flat contact portion and an upper contact portion; andsaid optical connection integrated material being recessed from acontact surface of said upper contact portion of said electricalconnection contact material ensuring effective electrical connection bemaintained with the module.
 2. The method as recited in claim 1 whereinproviding said contact includes providing an LGA spring type contact. 3.The method as recited in claim 1 wherein said integrated materialproviding an optical connection includes an acrylic material.
 4. Themethod as recited in claim 1 wherein said integrated material providingan optical connection includes a selected light pipe material.
 5. Themethod as recited in claim 1 wherein said integrated material providingan optical connection includes a generally central located light pipematerial.
 6. The method as recited in claim 1 wherein providing saidcontact includes providing a hybrid LGA contact with a light conduit ina middle contact portion.
 7. The method as recited in claim 1 whereinproviding said contact includes providing a hybrid LGA contact coated inlight pipe material.
 8. The method as recited in claim 1 whereinproviding said contact includes forming said contact with a hole andinjecting light pipe material into the hole.